Portion of a golf club head



FIG. 1 is a perspective view of a portion of a golf club head showing my new design;

FIG. 2 is a rear view thereof; and,

FIG. 3 is a bottom view thereof.

The broken line showing of the remainder of the golf club head is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a golf club head, as shown and described. 